/*
 * Copyright (c) 2018-2020 "Graph Foundation,"
 * Graph Foundation, Inc. [https://graphfoundation.org]
 *
 * This file is part of ONgDB.
 *
 * ONgDB is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
/*
 * Copyright (c) 2002-2020 "Neo4j,"
 * Neo4j Sweden AB [http://neo4j.com]
 *
 * This file is part of Neo4j.
 *
 * Neo4j is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.neo4j.codegen.source;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.tools.JavaFileObject;

import org.neo4j.codegen.ByteCodes;
import org.neo4j.codegen.ClassEmitter;
import org.neo4j.codegen.CodeGenerator;
import org.neo4j.codegen.CompilationFailureException;
import org.neo4j.codegen.TypeReference;

class SourceCodeGenerator extends CodeGenerator
{
    private final Configuration configuration;
    private final Map<TypeReference, StringBuilder> classes = new HashMap<>();
    private final SourceCompiler compiler;

    SourceCodeGenerator( ClassLoader parentClassLoader, Configuration configuration, SourceCompiler compiler )
    {
        super( parentClassLoader );
        this.configuration = configuration;
        this.compiler = compiler;
    }

    @Override
    protected ClassEmitter generate( TypeReference type, TypeReference base, TypeReference[] interfaces )
    {
        StringBuilder target = new StringBuilder();
        synchronized ( this )
        {
            StringBuilder old = classes.put( type, target );
            if ( old != null )
            {
                classes.put( type, old );
                throw new IllegalStateException( "Trying to generate class twice: " + type );
            }
        }
        ClassSourceWriter writer = new ClassSourceWriter( target, configuration );
        writer.declarePackage( type );
        writer.javadoc( "Generated by " + getClass().getName() );
        writer.publicClass( type );
        writer.extendClass( base );
        writer.implement( interfaces );
        writer.begin();
        return writer;
    }

    @Override
    protected Iterable<? extends ByteCodes> compile( ClassLoader classpathLoader ) throws CompilationFailureException
    {
        return compiler.compile( sourceFiles(), classpathLoader );
    }

    private synchronized List<JavaSourceFile> sourceFiles()
    {
        List<JavaSourceFile> sourceFiles = new ArrayList<>( classes.size() );
        for ( Map.Entry<TypeReference, StringBuilder> entry : classes.entrySet() )
        {
            TypeReference reference = entry.getKey();
            StringBuilder source = entry.getValue();
            configuration.visit( reference, source );
            sourceFiles.add( new JavaSourceFile( configuration.sourceBase().uri(
                    reference.packageName(), reference.name(), JavaFileObject.Kind.SOURCE ), source ) );
        }
        return sourceFiles;
    }
}
